The homopolar motor is driven by the Lorentz force. A conductor current flowing through it when placed in a magnetic field perpendicular to current conductor feels the force perpendicular to both magnetic field and current. This force provide torque around axis of rotation and conductor starts rotating.

Make your own today

Materials required

Helical wire

Battery

Disc magnet

Place the battery above disc magnet and arrange the helical wire such that all the parts of wire are perpendicular to the battery.